Tokyo (CNN) -- Japan announced Tuesday it is banning all shipments of cattle raised in the Fukushima Prefecture amid fears that the meat may have been contaminated from radiation at the crippled Fukushima Daiichi plant.
Chief Cabinet Secretary Yukio Edano made the announcement.
Last week, a Japanese health official downplayed the dangers after cesium contaminated meat from Fukushima cows was delivered to Japanese markets and probably ingested.
"If we were to eat the meat everyday, then it would probably be dangerous," Goshi Hosono, state minister in charge of consumer affairs and food-safety, said at a news conference on July 12.
"But if it is consumed only in small portions, I don't think it would have any long-lasting effects on the human body."
When the Fukushima Prefectural Government investigated the farm that was the source of the meat, it found cesium in cattle feed such as hay, with radiation levels as much as 57 times higher than the ceiling set by the Japanese government.
Up until now, cattle in Fukushima were only subject to a screening test, to inspect for radioactive particles adhering to the skin, and farmers were ordered to self-report how it the cattle feed was being stocked.
Yutaka Kashimura, Fukushima Prefecture's officer in charge of the livestock division, told CNN that the farmer may have given the cows hay that had been exposed to soil containing high levels of radiation. The farm is situated about 30 kilometers (18.6 miles) from the damaged Fukushima nuclear plant.
Four months after Japan's devastating earthquake and tsunami on March 11, operators at the Fukushima Daiichi nuclear power plant are still grappling with the crisis the disaster unleashed but say they are making slow progress.
The March 11 quake led to meltdowns at Fukushima Daiichi's three operating reactors when the tsunami knocked out their coolant systems, causing the worst nuclear accident since Chernobyl.
CNN's Kyung Lah and Nicolas Ito contributed to this report.